bidity (and now natality), the real test should be the ultimate effect on health (3). Adequate data on mortality, morbidity, and utilization of health services in LDC's do not exist. Instead, the following assumptions are made: with the same amount of service available, a population that is growing, and other conditions held constant, mortality and morbidity will increase; or if the amount of service is increased proportionately to the growth of population, mortality will be held constant. Conclusions must be drawn from limited health service data only. Although this is far from satisfactory, it is the present state of the art.
Any attempt to understand the consequences of population growth for health services should take into account direct demographic factors, such as total population, age structure, and geographic distribution, as well as direct developmental factors, such as national goals and achievements of specific levels of development, utilization of manpower, world technological developments, and levels of international assistance (Figure 1). What differentiates
Figure 1. Relationships between population growth and health services.
the consequences of population growth for health services from those for most other topics in this volume is the more immediate and direct effect that health services may have on population growth itself through both mortality and natality. In the LDC's today, the effects of population growth upon health services may depend significantly upon what alternative actions are taken by health services to bring natality in closer balance with decreasing mortality.
Objectives of Natality Control
Two essential distinctions between the social objectives of natality control on the one hand and of mortality and morbidity control on the other in-to reduce mortality and mor-